( 10 ) 
Illustrated by Fifty-three Plates and more than Eight Hundred]Woodcuts, giving 
figures of nearly 3000 Microscopic Objects. 8vo. Cloth. £2 12s. 6d. 
Griffith & Henfrey’s Micrographic Dictionary: 
A Guide to the Examination and Investigation of the Structure 
and Nature of Microscopic Objects. 
FOURTH EDITION. 
Edited by J. W. GRIFFITH, M.D., &c., assisted by The Rev. M. J. BERKELEY, 
M.A., F.L.S., and T. RUPERT JONES, F.R.S., F.G.S., &c. 
“ A valuable handbook even for the advanced student of nature, to whom, moreover, the having such a 
vast mass ot scattered zoological and botanical knowledge brought together within the compass of a single 
volume cannot but be exceedingly convenient .” — Annals of Natural History . 
LONDON: GURNEY & JACKSON, 1, PATERNOSTER ROW. 
(Successors to Me. VAN VOORST.) 
SWIFT & SON’S New 1/12 in. Homogeneous Immersion Objective of 
1*25 N.A., in which, the New Abbe-Schott glass is used, price £5 5s. 
This lens Swift & Son guarantee to be equal to any other Homogeneous Immersion 
Objective of the same N.A. 
Swift & Son are continually receiving testimonials in praise of the above Objective. 
A New 1/12 in. Apochromatic Homogeneous Immersion Objective of 
1-4 N.A., £16. 
Compensating Eye-pieces, magnifying 10, 20, and 30 times, price 
each, £2. 
These Eye-pieces also give excellent results with Objectives made with the old Media. 
Projection Eye-pieces for Photo-Micrography, magnifying 3 and 
6 times, each £2. 
For ‘particulars of Professor Croolcshank’s Bacteriological Microscope, and Medical 
Press Comments , send for Circular. 
UNIVERSITY OPTICAL WORKS, 
81, TOTTENHAM COURT ROAD, LONDON, W. 
ROYAL MICROSCOPICAL SOCIETY. 
MEETINGS EOE 1891, at 8 p.m. 
Wednesday, January . . . . 21 
( Annual Meeting for Election of 
Officers and Council.') 
„ February . . . . 18 
„ March . . . . 18 
„ April 15 
Wednesday, 
May . . 
.. 20 
June . . 
.. 17 
» 
October 
.. 21 
November . . 
. . 18 
December . . 
.. 16 
Fellows intending to exhibit any Instruments, Objects, &c., or to bring 
forward any Communication at the Ordinary Meetings, will much facilitate 
the arrangement of the business thereat if they will inform the Secretaries of 
their intention two clear days at least before the Meeting. 
Authors of Papers printed in the Transactions are entitled to 20 copies 
of their communications gratis. Extra copies can be had at the price of 
10s. 6d. per half-sheet of 8 pages, or less, including cover, for a minimum 
number of 50 copies, and 6 s. per 100 plates, if plain. Prepayment by 
P.O.O. is requested. 
